PLEASE HELP ASAP, 100 POINTS GIVEN

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?

Which of the following is missing in the explicit formula for the compound interest geometric sequence below?